In the case where a carcass of livestock such as a pig, a cow, or a sheep is served as meat, it is required to break down a carcass of livestock and to separate meat parts from bone parts, which is referred to as a deboning process. A deboning process performed by manpower is hard work. Thus, the process has been increasingly automated by machines. In recent years, there are some types of deboning process that are automated in most parts except for pre-processing, depending on the kind of bone-in meat. In an automated deboning apparatus, for instance, a piece of bone-in meat to be processed is deboned while being conveyed in a state of being suspended from a clamper. In a deboning process of an arm part or a thigh part of a carcass of live stock, the shape of the arm part or the thigh part varies between the left and right sides of a carcass. Thus, a deboning process with high yields may not be performed if left/right determination is not performed beforehand. As the case may be, an error in the left/right determination may lead to an event in which operation of the deboning apparatus needs to be stopped.
The applicant has developed automatic deboning techniques for a carcass of livestock, including deboning processes for such an arm part and a thigh part. For example, Patent Document 1 discloses a deboning technique for a thigh part of a carcass of livestock. Patent Document 1 discloses a left/right determination method for a thigh part, which is to be performed as a previous step before the deboning process. This left/right determination method is for a thigh part after its haunch bone is removed by pre-processing. The method utilizes the position of a pocket that is formed on a bottom part after removing a haunch bone, the position being different between a left thigh part and a right thigh part, to determine whether a thigh part is from the left side or the right side of a carcass by detecting the position of the pocket using a sensing plate.